idnits 2.17.1 draft-ietf-xrblock-rtcp-xr-jb-09.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (March 16, 2013) is 4058 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Looks like a reference, but probably isn't: '1' on line 195 ** Obsolete normative reference: RFC 4566 (Obsoleted by RFC 8866) ** Downref: Normative reference to an Informational RFC: RFC 6709 Summary: 2 errors (**), 0 flaws (~~), 1 warning (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Audio/Video Transport Working Group A. Clark 3 Internet-Draft Telchemy 4 Intended status: Standards Track V. Singh 5 Expires: September 17, 2013 Aalto University 6 Q. Wu 7 Huawei 8 March 16, 2013 10 RTP Control Protocol (RTCP) Extended Report (XR) Block for Jitter Buffer 11 Metric Reporting 12 draft-ietf-xrblock-rtcp-xr-jb-09.txt 14 Abstract 16 This document defines an RTP Control Protocol (RTCP) Extended Report 17 (XR) Block that allows the reporting of Jitter Buffer metrics for a 18 range of RTP applications. 20 Status of this Memo 22 This Internet-Draft is submitted in full conformance with the 23 provisions of BCP 78 and BCP 79. 25 Internet-Drafts are working documents of the Internet Engineering 26 Task Force (IETF). Note that other groups may also distribute 27 working documents as Internet-Drafts. The list of current Internet- 28 Drafts is at http://datatracker.ietf.org/drafts/current/. 30 Internet-Drafts are draft documents valid for a maximum of six months 31 and may be updated, replaced, or obsoleted by other documents at any 32 time. It is inappropriate to use Internet-Drafts as reference 33 material or to cite them other than as "work in progress." 35 This Internet-Draft will expire on September 17, 2013. 37 Copyright Notice 39 Copyright (c) 2013 IETF Trust and the persons identified as the 40 document authors. All rights reserved. 42 This document is subject to BCP 78 and the IETF Trust's Legal 43 Provisions Relating to IETF Documents 44 (http://trustee.ietf.org/license-info) in effect on the date of 45 publication of this document. Please review these documents 46 carefully, as they describe your rights and restrictions with respect 47 to this document. Code Components extracted from this document must 48 include Simplified BSD License text as described in Section 4.e of 49 the Trust Legal Provisions and are provided without warranty as 50 described in the Simplified BSD License. 52 Table of Contents 54 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 55 1.1. Jitter Buffer Metrics Block . . . . . . . . . . . . . . . 3 56 1.2. RTCP and RTCP XR Reports . . . . . . . . . . . . . . . . . 3 57 1.3. Performance Metrics Framework . . . . . . . . . . . . . . 3 58 1.4. Applicability . . . . . . . . . . . . . . . . . . . . . . 3 59 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 60 2.1. Standards Language . . . . . . . . . . . . . . . . . . . . 4 61 3. Jitter Buffer Operation . . . . . . . . . . . . . . . . . . . 5 62 3.1. Idealized Jitter Buffer . . . . . . . . . . . . . . . . . 5 63 3.2. Fixed Jitter Buffer . . . . . . . . . . . . . . . . . . . 6 64 3.3. Adaptive Jitter Buffer . . . . . . . . . . . . . . . . . . 6 65 4. Jitter Buffer Metrics Block . . . . . . . . . . . . . . . . . 7 66 4.1. Report Block Structure . . . . . . . . . . . . . . . . . . 7 67 4.2. Definition of Fields in Jitter Buffer Metrics Block . . . 7 68 5. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 10 69 5.1. SDP rtcp-xr-attrib Attribute Extension . . . . . . . . . . 10 70 5.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . . 10 71 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 72 6.1. New RTCP XR Block Type value . . . . . . . . . . . . . . . 11 73 6.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 11 74 6.3. Contact information for registrations . . . . . . . . . . 11 75 7. Security Considerations . . . . . . . . . . . . . . . . . . . 12 76 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 13 77 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14 78 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 79 10.1. Normative References . . . . . . . . . . . . . . . . . . . 15 80 10.2. Informative References . . . . . . . . . . . . . . . . . . 15 81 Appendix A. Metrics represented using RFC6390 Template . . . . . 16 82 Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 19 83 B.1. draft-ietf-xrblock-rtcp-xr-jb-09 . . . . . . . . . . . . . 19 84 B.2. draft-ietf-xrblock-rtcp-xr-jb-08 . . . . . . . . . . . . . 19 85 B.3. draft-ietf-xrblock-rtcp-xr-jb-07 . . . . . . . . . . . . . 19 86 B.4. draft-ietf-xrblock-rtcp-xr-jb-05 . . . . . . . . . . . . . 19 87 B.5. draft-ietf-xrblock-rtcp-xr-jb-03 . . . . . . . . . . . . . 19 88 B.6. draft-ietf-xrblock-rtcp-xr-jb-02 . . . . . . . . . . . . . 19 89 B.7. draft-ietf-xrblock-rtcp-xr-jb-01 . . . . . . . . . . . . . 20 90 B.8. draft-ietf-xrblock-rtcp-xr-jb-00 . . . . . . . . . . . . . 20 91 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 21 93 1. Introduction 95 1.1. Jitter Buffer Metrics Block 97 This document defines a new block type to augment those defined in 98 [RFC3611], for use in a range of RTP applications. 100 The new block type provides information on jitter buffer 101 configuration and performance. 103 The metric belongs to the class of transport-related end system 104 metrics defined in [RFC6792]. 106 Instances of this Metrics Block refer by Synchronization source 107 (SSRC) to the separate auxiliary Measurement Information block 108 [RFC6776] which contains information such as the SSRC of the measured 109 stream, and RTP sequence numbers and time intervals indicating the 110 span of the report. 112 1.2. RTCP and RTCP XR Reports 114 The use of RTCP for reporting is defined in [RFC3550]. [RFC3611] 115 defines an extensible structure for reporting using an RTCP Extended 116 Report (XR). This document defines a new Extended Report block for 117 use with [RFC3550] and [RFC3611]. 119 1.3. Performance Metrics Framework 121 The Performance Metrics Framework [RFC6390] provides guidance on the 122 definition and specification of performance metrics. The RTP 123 Monitoring Architectures [RFC6792] provides guideline for reporting 124 block format using RTCP XR. Metrics described in this draft are in 125 accordance with the guidelines in [RFC6390]and [RFC6792]. 127 1.4. Applicability 129 Real-time applications employ a jitter buffer to absorb jitter 130 introduced on the path from source to destination. These metrics are 131 used to report how the jitter buffer at the receiving end of RTP 132 stream behaves as a result of jitter in the network and are 133 applicable to a range of RTP applications. 135 These metrics reflect how terminal-related factors affect real-time 136 application quality and are useful to provide better end-user quality 137 of experience (QoE). 139 2. Terminology 141 2.1. Standards Language 143 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 144 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 145 document are to be interpreted as described in RFC 2119 [RFC2119]. 147 3. Jitter Buffer Operation 149 A jitter buffer is required to absorb delay variation in network 150 delivery of media packets. A jitter buffer works by holding media 151 data for a period of time after it is received and before it is 152 played out. Packets that arrive early are held in the jitter buffer 153 longer. If packets arrive too early they may be discarded if there 154 is no available jitter buffer space. If packets are delayed 155 excessively by the network they may be discarded if they miss their 156 playout time. 158 Overall user perceived delay = network round trip delay + local 159 (jitter buffer (nominal) delay + encoder serialization delay) + 160 remote (jitter buffer (nominal) delay + encoder serialization delay) 162 The jitter buffer can be considered as a time window with early edge 163 aligned with the delay corresponding to the earliest arriving packet 164 and late edge representing the maximum permissible delay before a 165 late arriving packet would be discarded. The delay applied to 166 packets that arrive at their expected time is known as the Nominal 167 Delay and this is equivalent to the late edge. 169 The reference for the expected arrival time may, for example, be the 170 first packet in the session or the running average delay. If all 171 packets arrived at their expected arrival time then then every packet 172 would be held in the jitter buffer exactly the Nominal Delay. 174 The Jitter Buffer maximum delay is the delay that is applied to an 175 earliest arriving packet that is not discarded and corresponds to the 176 early edge of the jitter buffer time window. 178 3.1. Idealized Jitter Buffer 180 In practice jitter buffer implementations vary considerably however 181 should behave in a manner conceptually consistent with an idealized 182 jitter buffer described as follows: 184 (i). Receive the first packet and delay playout by D ms. Keep 185 the RTP timestamp and receive time as a reference. 187 RTP TS[1] 189 receive time[1] 191 Assume that both are normalized in ticks. 193 (ii). Receive the next packet 194 (iii). Calculate r = RTP TS[n] - RTP TS[1] and t = receive 195 time[n] - receive time[1]. If r = t then the packet arrived on 196 time. If r < t then the packet arrived late and if r > t then the 197 packet arrived early. 199 (iv). Delay playout of packet by D + (r -t) 201 (v). Go back to (ii) 203 Note that this idealized implementation assumes that the sender's RTP 204 clock is synchronized to the clock in the receiver which is used to 205 timestamp packet arrivals. If there is no such inherent 206 synchronization, the system may need to use an adaptive jitter buffer 207 or other techniques to ensure reliable reception. 209 3.2. Fixed Jitter Buffer 211 The fixed jitter buffers have a fixed size and the packets leaving 212 the jitter buffer have a constant delay. 214 3.3. Adaptive Jitter Buffer 216 An adaptive jitter buffer have variable size and variable delay. It 217 allows the nominal delay to be set to a low value initially, to 218 minimize user perceived delay, however can automatically extend the 219 late edge (and possibly also retract the early edge) of buffer window 220 if a significant proportion of packets are arriving late (and hence 221 being discarded). 223 4. Jitter Buffer Metrics Block 225 This block describes the configuration and operating parameters of 226 the jitter buffer in the receiver of the RTP end system or RTP mixer 227 which sends the report. Instances of this Metrics Block refer by 228 SSRC to the separate auxiliary Measurement Information block 229 [RFC6776] which describes the measurement interval in use. This 230 Metrics Block relies on the measurement interval in the Measurement 231 Information block indicating the span of the report and should be 232 sent in the same compound RTCP packet as the measurement information 233 block. If the measurement interval is not received in the same 234 compound RTCP packet as this Metrics Block, this Metrics Block should 235 be discarded. 237 4.1. Report Block Structure 239 JB Metrics Block 241 0 1 2 3 242 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 243 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 244 | BT=NJB | I |C| Rsvd. | block length=3 | 245 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 246 | SSRC of Source | 247 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 248 | JB nominal | JB maximum | 249 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 250 | JB high water mark | JB low water mark | 251 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 253 Figure 1: Report Block Structure 255 4.2. Definition of Fields in Jitter Buffer Metrics Block 257 Block type (BT): 8 bits 259 A Jitter Buffer Metrics Report Block is identified by the constant 260 NJB. 262 [Note to RFC Editor: please replace NJB with the IANA provided 263 RTCP XR block type for this block.] 265 Interval Metric flag (I): 2 bits 267 This field is used to indicate whether the Jitter Buffer metrics 268 are Sampled, Interval or Cumulative metrics: 270 I=01: Sampled Value - the reported value is a sampled 271 instantaneous value. 273 I=10: Interval Duration - the reported value applies to the 274 most recent measurement interval duration between successive 275 metrics reports. 277 I=11: Cumulative Duration - the reported value applies to the 278 accumulation period characteristic of cumulative measurements. 280 Jitter Buffer Configuration (C): 1 bit 282 This field is used to identify the jitter buffer method in use at 283 the receiver, according to the following code: 285 0 = Fixed jitter buffer 287 1 = Adaptive jitter buffer 289 Reserved (Rsvd.): 5 bits 291 These bits are reserved. They MUST be set to zero by senders 292 ignored by receivers (See [RFC6709] section 4.2). 294 Block Length: 16 bits 296 The length of this report block in 32-bit words, minus one, in 297 accordance with the definition in [RFC3611]. This field MUST be 298 set to 3 to match the fixed length of the report block. 300 jitter buffer nominal delay (JB nominal): 16 bits 302 This is the current nominal jitter buffer delay in milliseconds, 303 which corresponds to the nominal jitter buffer delay for packets 304 that arrive exactly on time. It is calculated based on the time 305 spend in the jitter buffer for the packet that arrives exactly on 306 time. This parameter MUST be provided for both fixed and adaptive 307 jitter buffer implementations. 309 If the measured value exceeds 0xFFFD, the value 0xFFFE MUST be 310 reported to indicate an over-range measurement. If the 311 measurement is unavailable, the value 0xFFFF MUST be reported. 313 jitter buffer maximum delay (JB maximum): 16 bits 315 This is the current maximum jitter buffer delay in milliseconds 316 which corresponds to the earliest arriving packet that would not 317 be discarded. It is calculated based on the time spent in the 318 jitter buffer for the earliest arriving packet In simple queue 319 implementations this may correspond to the size of the jitter 320 buffer. In adaptive jitter buffer implementations, this value may 321 vary dynamically. This parameter MUST be provided for both fixed 322 and adaptive jitter buffer implementations. 324 If the measured value exceeds 0xFFFD, the value 0xFFFE MUST be 325 reported to indicate an over-range measurement. If the 326 measurement is unavailable, the value 0xFFFF MUST be reported. 328 jitter buffer high water mark (JB high water mark): 16 bits 330 This is the highest value of the jitter buffer nominal delay in 331 milliseconds which occurred at any time during the reporting 332 interval. This parameter MUST be provided for adaptive jitter 333 buffer implementations and its value MUST be set to JB maximum for 334 fixed jitter buffer implementations. 336 If the measured value exceeds 0xFFFD, the value 0xFFFE MUST be 337 reported to indicate an over-range measurement. If the 338 measurement is unavailable, the value 0xFFFF MUST be reported. 340 jitter buffer low water mark (JB low water mark): 16 bits 342 This is the lowest value of the jitter buffer nominal delay in 343 milliseconds which occurred at any time during the reporting 344 interval. This parameter MUST be provided for adaptive jitter 345 buffer implementations and its value MUST be set to JB maximum for 346 fixed jitter buffer implementations. 348 If the measured value exceeds 0xFFFD, the value 0xFFFE MUST be 349 reported to indicate an over-range measurement. If the 350 measurement is unavailable, the value 0xFFFF MUST be reported. 352 5. SDP Signaling 354 [RFC3611] defines the use of SDP (Session Description Protocol) 355 [RFC4566] for signaling the use of XR blocks. However XR blocks MAY 356 be used without prior signaling (see section 5 of RFC3611). 358 5.1. SDP rtcp-xr-attrib Attribute Extension 360 This section augments the SDP [RFC4566] attribute "rtcp-xr" defined 361 in [RFC3611] by providing an additional value of "xr-format" to 362 signal the use of the report block defined in this document. 364 xr-format =/ xr-jb-block 366 xr-jb-block = "jitter-bfr" 368 5.2. Offer/Answer Usage 370 When SDP is used in offer-answer context, the SDP Offer/Answer usage 371 defined in [RFC3611] for unilateral "rtcp-xr" attribute parameters 372 applies. For detailed usage of Offer/Answer for unilateral 373 parameter, refer to section 5.2 of [RFC3611]. 375 6. IANA Considerations 377 New block types for RTCP XR are subject to IANA registration. For 378 general guidelines on IANA considerations for RTCP XR, refer to 379 [RFC3611]. 381 6.1. New RTCP XR Block Type value 383 This document assigns the block type value NJB in the IANA "RTCP XR 384 Block Type Registry" to the "JB Metrics Block". 386 [Note to RFC Editor: please replace NJB with the IANA provided RTCP 387 XR block type for this block.] 389 6.2. New RTCP XR SDP Parameter 391 This document also registers a new parameter "jitter-bfr" in the 392 "RTCP XR SDP Parameters Registry". 394 6.3. Contact information for registrations 396 The contact information for the registrations is: 398 Qin Wu (sunseawq@huawei.com) 399 101 Software Avenue, Yuhua District 400 Nanjing, Jiangsu 210012 401 China 403 7. Security Considerations 405 It is believed that this proposed RTCP XR report block introduces no 406 new security considerations beyond those described in [RFC3611]. 407 This block does not provide per-packet statistics so the risk to 408 confidentiality documented in Section 7, paragraph 3 of [RFC3611] 409 does not apply. 411 8. Contributors 413 Geoff Hunt wrote the initial draft of this document. 415 9. Acknowledgments 417 The authors gratefully acknowledge reviews and feedback provided by 418 Bruce Adams, Philip Arden, Amit Arora, Bob Biskner, Kevin Connor, 419 Claus Dahm, Randy Ethier, Roni Even, Jim Frauenthal, Albert Higashi, 420 Tom Hock, Shane Holthaus, Paul Jones, Rajesh Kumar, Keith Lantz, 421 Mohamed Mostafa, Amy Pendleton, Colin Perkins, Mike Ramalho, Ravi 422 Raviraj, Albrecht Schwarz, Tom Taylor, Hideaki Yamada,Claire Bi,Colin 423 Perkin, Dan Romascanu, Kevin Gross and Glen Zorn. 425 10. References 427 10.1. Normative References 429 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 430 Requirement Levels", March 1997. 432 [RFC3550] Schulzrinne, H., "RTP: A Transport Protocol for Real-Time 433 Applications", RFC 3550, July 2003. 435 [RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control 436 Protocol Extended Reports (RTCP XR)", November 2003. 438 [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session 439 Description Protocol", July 2006. 441 [RFC6709] Carpenter, B., Aboba, B., and S. Cheshire, "Design 442 Considerations for Protocol Extensions", RFC 6709, 443 September 2012. 445 [RFC6776] Wu, Q., "Measurement Identity and information Reporting 446 using SDES item and XR Block", RFC 6776, August 2012. 448 10.2. Informative References 450 [RFC6390] Clark, A. and B. Claise, "Framework for Performance Metric 451 Development", RFC 6390, October 2011. 453 [RFC6792] Hunt, G., Wu, Q., and P. Arden, "Monitoring Architectures 454 for RTP", RFC 6792, November 2012. 456 Appendix A. Metrics represented using RFC6390 Template 458 a. jitter buffer nominal delay Metric 460 * Metric Name: jitter buffer nominal delay 462 * Metric Description: The "expected arrival time" is the time 463 that a RTP packet would arrive if there was no delay 464 variation. The delay applied to packets that arrive at their 465 expected time is known as the Nominal Delay. 467 * Method of Measurement or Calculation: See section 4.2, jitter 468 buffer nominal delay definition for measurement or calculation 469 method. 471 * Units of Measurement: See section 4.2, jitter buffer nominal 472 delay definition for units of measurement. 474 * Measurement Point(s) with Potential Measurement Domain: See 475 section 4, 1st paragraph for measurement point. 477 * Measurement Timing: See section 4, 1st paragraph for 478 measurement timing and section 4.2 paragraph for Interval 479 Metric flag. 481 * Use and applications: See section 1.4 for use and 482 applications. 484 * Reporting model: See RFC3611 for reporting model. 486 b. jitter buffer maximum delay Metric 488 * Metric Name: jitter buffer maximum delay 490 * Metric Description: It is the current maximum jitter buffer 491 delay for RTP traffic which corresponds to the earliest 492 arriving packet that would not be discarded. 494 * Method of Measurement or Calculation: See section 4.2, jitter 495 buffer maximum delay definition and section 3, the last 496 paragraph for measurement or calculation method. 498 * Units of Measurement: See section 4.2, jitter buffer maximum 499 delay definition for units of measurement. 501 * Measurement Point(s) with Potential Measurement Domain: See 502 section 4, 1st paragraph for measurement point. 504 * Measurement Timing: See section 4, 1st paragraph for 505 measurement timing and section 4.2 paragraph for Interval 506 Metric flag. 508 * Use and applications: See section 1.4 for use and 509 applications. 511 * Reporting model: See RFC3611 for reporting model. 513 c. jitter buffer high water mark Metric 515 * Metric Name: jitter buffer high water mark 517 * Metric Description: It is the highest value of the jitter 518 buffer nominal delay for RTP traffic which occurred at any 519 time during the reporting interval. 521 * Method of Measurement or Calculation: See section 4.2, jitter 522 buffer high water mark definition for measurement or 523 calculation method. 525 * Units of Measurement: See section 4.2, jitter buffer nominal 526 delay definition for units of measurement. 528 * Measurement Point(s) with Potential Measurement Domain: See 529 section 4, 1st paragraph for measurement point. 531 * Measurement Timing: See section 4, 1st paragraph for 532 measurement timing and section 4.2 paragraph for Interval 533 Metric flag. 535 * Use and applications: See section 1.4 for use and 536 applications. 538 * Reporting model: See RFC3611 for reporting model. 540 d. jitter buffer low water mark Metric 542 * Metric Name: jitter buffer low water mark 544 * Metric Description: It is the lowest value of the jitter 545 buffer nominal delay for RTP traffic which occurred at any 546 time during the reporting interval. 548 * Method of Measurement or Calculation: See section 4.2, jitter 549 buffer low water mark definition for measurement or 550 calculation method. 552 * Units of Measurement: See section 4.2, jitter buffer low water 553 mark definition for units of measurement. 555 * Measurement Point(s) with Potential Measurement Domain: See 556 section 4, 1st paragraph for measurement point. 558 * Measurement Timing: See section 4, 1st paragraph for 559 measurement timing and section 4.2 paragraph for Interval 560 Metric flag. 562 * Use and applications: See section 1.4 for use and 563 applications. 565 * Reporting model: See RFC3611 for reporting model. 567 Appendix B. Change Log 569 Note to the RFC-Editor: please remove this section prior to 570 publication as an RFC. 572 B.1. draft-ietf-xrblock-rtcp-xr-jb-09 574 The following are the major changes to previous version : 576 o Incorporate proposed changes by Kevin and proposed text by Alan to 577 address interoperability report issue. 579 o Add new appendix to format metrics using RFC6390 template. 581 B.2. draft-ietf-xrblock-rtcp-xr-jb-08 583 The following are the major changes to previous version : 585 o Rewrote descriptive text and definitions for clarification. 587 B.3. draft-ietf-xrblock-rtcp-xr-jb-07 589 The following are the major changes to previous version : 591 o Add one new section to discuss jitter buffer operation. 593 B.4. draft-ietf-xrblock-rtcp-xr-jb-05 595 The following are the major changes to previous version : 597 o Some editorial change changes based on the discussion with Glen 598 and Kevin on the list. 600 B.5. draft-ietf-xrblock-rtcp-xr-jb-03 602 The following are the major changes to previous version : 604 o Reduce the "jb cfg" to 1-bit based on discussion in the WGLC. 606 o Other editorial change changes aligning with PDV,Delay draft. 608 B.6. draft-ietf-xrblock-rtcp-xr-jb-02 610 The following are the major changes to previous version : 612 o Add some explanation text in the SDP offer/answer section. 614 o Add some text in applicability section to explain the use to 615 report jitter buffer metrics. 617 o Other editorial change changes aligning with PDV,Delay draft. 619 B.7. draft-ietf-xrblock-rtcp-xr-jb-01 621 The following are the major changes to previous version : 623 o Outdated reference update 625 o Add one Editor notes to ask clarification on the use of reporting 626 jitter buffer metrics. 628 o Other Editorial changes. 630 B.8. draft-ietf-xrblock-rtcp-xr-jb-00 632 The following are the major changes to previous version : 634 o Boilerplate updates. 636 o references updates 638 o allocate 32 bit field in report block for SSRC 640 o Other editorial changes to get alignment with MONARCH draft. 642 Authors' Addresses 644 Alan Clark 645 Telchemy Incorporated 646 2905 Premiere Parkway, Suite 280 647 Duluth, GA 30097 648 USA 650 Email: alan.d.clark@telchemy.com 652 Varun Singh 653 Aalto University 654 School of Electrical Engineering 655 Otakaari 5 A 656 Espoo, FIN 02150 657 Finland 659 Email: varun@comnet.tkk.fi 661 Qin Wu 662 Huawei 663 101 Software Avenue, Yuhua District 664 Nanjing, Jiangsu 210012 665 China 667 Email: sunseawq@huawei.com